Train modeling is a unique hobby that provides a creative outlet for children and adults alike. Various model track pieces and accessories are assembled into a model layout on which model trains run. The layout can be modeled in various scales or gauges. HO is one of the most popular scales among train modelers. In HO scale, every 1 inch represents 87 inches and the rails on HO scale train track are only approximately 0.65 inches apart. Needless to say, the train wheels and other components on an HO scale layout are relatively small and can be difficult to clean. Smaller scales, such as N scale, are also popular.
Model trains are often powered by electricity. The train engine typically has at least two pairs of metal wheels and houses an electric motor that causes the wheels to turn. The motor in the train engine is powered by an electric current flowing through the rails of the train track. The wheels each have a rim and a rail contact surface. The rim guides the wheel along the track rail while the rail contact surface is in electrical contact with the track rail. Because the wheels are metal, they have a tendency to oxidize and often become coated with adhesives, oil, grease and other materials used on the model layout. It is important that the track rails and the rail contact surfaces of the wheels are clean as dirt buildup will interfere with the electrical connection and negatively affect performance.
Any number of train cars can be hitched to the engine and pulled around the track. Each train car has at least two pairs of non-motorized, free-spinning wheels. Model train car wheels can be made of metal and used to conduct electric current from the track into the car to power accessories such as lights. Some model train car wheels are plastic and create static electricity as they travel around the track, which attracts dust and other contaminants to the wheels and track. Regardless of what the wheels are made, the rail contact surfaces should be kept clean to prevent soiling or damaging the rails, causing uneven wear and tear to the wheels or rails, or negatively impacting conductivity between the car accessory and the track. Excessive dirt buildup can also cause derailment.
Most model trains operate on a two-rail track system. In a two-rail system, the track has two metal rails through which an electric current generated by a power supply flows. When a train engine is placed on the track, the current flows up from a first rail, through the metal wheels of the train and to the electric motor. The current is returned through the wheels on the other side of the engine and into a second rail, where it flows back to the power supply thereby completing the circuit. The electric motor inside the train engine, powered by the electric current, causes the train engine wheels to turn.
Some model trains operate on a three-rail track system. In a three-rail system, the track has three metal rails through which an electric current generated by a power supply flows. A train engine designed to run on a three-rail track has a metal skid between the wheels that is in electrical contact with the middle rail when the train engine is placed on the track. Electric current flows up from the middle rail, through the metal skid of the engine and to the electric motor. The current is returned through the wheels to the outer rails where it flows back to the power supply thereby completing the circuit. The electric motor inside the train engine, powered by the electric current, causes the train engine wheels to turn.